Prepare for upgrade to React 19

Co-authored-by: ayumi-signal <ayumi@signal.org>

ts/components/conversation/MessageContextMenu.dom.tsx

@@ -49,7 +49,7 @@ export function MessageContextMenu({
   onPinMessage,
   onUnpinMessage,
   children,
-}: MessageContextMenuProps): JSX.Element {
+}: MessageContextMenuProps): React.JSX.Element {
   return (
     <AxoMenuBuilder.Root renderer={renderer} onOpenChange={onOpenChange}>
       <AxoMenuBuilder.Trigger disabled={disabled}>